<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        //1,绝对值方法
        console.log(Math.abs(1)); //1
        console.log(Math.abs(-1)); //1
        console.log(Math.abs('1')); //1  隐式转换  会把字符串型转换为数字型
        //2，取三个整数的方法
        //(1)Math.floor()  向下取整  最小取值
        console.log(Math.floor(1.1)); //1
        console.log(Math.floor(1.9)); //1
        //(2),Math.ceil()  向上取整  最大取值
        console.log(Math.ceil(1.1)); //2
        console.log(Math.ceil(1.9)); //2
        //(3),Math.round()  四舍五入  其他数字都是四舍五入
        console.log(Math.round(1.1)); //1
        console.log(Math.round(1.9)); //2
        console.log(Math.round(-1.1)); //-1
        console.log(Math.round(-1.5)); //-1
        console.log(Math.round(-1.9)); //-2
    </script>
</head>

<body>

</body>

</html>